CDISC Standards are internationally harmonized data standards of the Clinical Data Interchange Standards Consortium for clinical and nonclinical research. They define models, data structures, terminologies and metadata so that study data can be collected, exchanged, analyzed and provided for regulatory review consistently. CDISC is therefore a family of standards and not a single data format.
The model family systematically classified
CDASH, the Clinical Data Acquisition Standards Harmonization Implementation Guide, is used for standardized data collection. CDASH supports uniform data collection formats and ensures traceability from collection to submission data. Controlled Terminology defines permitted standardized values for CDISC variables. SDTM, the Study Data Tabulation Model, organizes and formats clinical study tabulation data in standardized domains for review and submission.
ADaM, the Analysis Data Model, describes analysis-ready datasets and the associated metadata. A core principle is transparent traceability of analysis results through ADaM to SDTM and onward to data collection. Define-XML provides machine-readable metadata for datasets and variables. SEND, the Standard for Exchange of Nonclinical Data, is an SDTM-based implementation for nonclinical studies. The family is complemented by therapeutic area standards, implementation guides and conformance rules.
Standardization, versions and submission
CDISC standards create a common semantic and structural understanding, but they do not replace the scientific definition of the protocol. Before implementation, the concepts collected, units, time references and derivations must be clearly defined. For each study, it must be determined which models, implementation guides, controlled terminologies and versions apply. Deviations or unavoidable mapping decisions are described transparently in specifications and metadata.
CDISC standards play a central role in regulatory submissions. For FDA, CDISC identifies Controlled Terminology, SEND, SDTM, ADaM and Define-XML in particular as required standards; the specific versions and technical expectations must be checked in the applicable regulatory catalogs and guidance. For PMDA, CDISC names, among others, SDTM, ADaM, Define-XML and Analysis Results Metadata. For European procedures, the data standard should be determined based on the specific submission strategy and regulatory expectations, rather than being derived broadly from US requirements.
The standards family also represents more than tabular datasets. Models, implementation guides, controlled terminology, conformance rules and metadata work together. CDASH describes data collection, SDTM standardized tabulation, ADaM analysis-ready representation and Define-XML the electronic description of the data. This relationship enables reviewers to understand data structures and derivations systematically, but requires careful implementation for each study.
Conformance is more than passing technical checks. Rules can identify structural errors and impermissible values, while the scientific meaning, completeness of the source and suitability of a mapping must also be assessed. Transparent mapping shows which source elements are transferred to which standard variable and which derivations take place in the process. This preserves the original meaning of the data.
Distinction from data management
CDISC standards are rules for the structure, presentation and description of data. Data management, by contrast, is the operational process that plans and controls data flows: eCRF design, data validation, query management, coding, data cleaning, database lock and handovers are part of it. CDISC can structure and facilitate these activities, but it is neither a data management plan nor a substitute for roles, standard operating procedures and quality controls.
The distinction is important in practice. An SDTM-compliant table cannot correct missing or erroneous source data, and a well-managed data management process does not automatically produce a submission-ready SDTM or ADaM package. Standard strategy and data management must therefore be planned together at an early stage: from CDASH-oriented collection design through mapping and controlled terminology to conformance checks, Define-XML and analysis traceability.
Relevance for clinical trials
Early CDISC planning reduces avoidable recoding and facilitates consistent handovers between data collection, data management, biostatistics and medical writing. It does not create automatic data quality, but makes data structures, derivations and metadata easier for reviewers to understand. Particularly important are traceable mapping specifications, versioned controlled terminology, documented deviations and the verifiable connection between source, SDTM, ADaM and analysis result.
Full-service CROs such as Mediconomics support CDISC strategy and specifications, CDASH-oriented eCRF design, SDTM mapping, ADaM planning, programming and conformance checks. They coordinate data management and biostatistics, create or review Define-XML and Reviewer Guides, and document the traceability of important variables and analysis derivations for the clinical study report or a regulatory submission.
Frequently Asked Questions (FAQ)
What is the difference between SDTM and ADaM?
SDTM standardizes tabulation data for review and submission. ADaM organizes analysis-ready datasets and metadata so that analysis results can be generated and reviewed transparently.
Is SEND part of the clinical CDISC standards?
SEND belongs to the CDISC standards family but is intended for nonclinical data. It is based on SDTM and supports the standardized presentation of nonclinical study tabulation data.
Does CDISC replace a data management system?
No. CDISC defines data standards. A data management system and the associated processes control the operational collection, review, clarification and finalization of study data.
Regulatory references
- CDISC Standards — classifies Foundational Standards, Controlled Terminology and standards for data exchange.
- CDISC SDTM — defines the model for organizing and formatting clinical tabulation data.
- CDISC ADaM — describes analysis-ready datasets, metadata and traceability to SDTM.
- CDISC SEND — describes the SDTM-based exchange standard for nonclinical data.
- FDA Data Standards Catalog — specifies the data standards and supported versions applicable to FDA submissions.